The present invention relates to a cooling device having three storage zones that are insulated from each other and are cooled by means of evaporators through which a coolant flows.
With a conventional cooling device of this type, the evaporators of the three storage zones are connected one behind the other in a coolant circuit. The cooling power of the evaporator furthest downstream in the coolant circuit is controlled by way of the quantity of coolant circulating in the coolant circuit. To this end, a coolant collector is arranged in a high pressure region of the coolant circuit. If this stores liquid coolant, the coolant circuit operates in an underfilled state, which results in the coolant essentially already being evaporated before it reaches the evaporator which is arranged furthest downstream. The cooling power therefore concentrates on the storage zones cooled by the evaporators arranged further upstream. Since independent control of the cooling power is not possible in the two storage zones upstream, the cooling power of this evaporator and the coolant requirement of these storage zones have to be attuned precisely to one another in order to prevent one or other storage zones from being undercooled.
DE 197 56 861A1 attempts to eliminate this disadvantage by a second injection point being provided on the evaporator arranged furthest upstream in the case of a cooling device having three storage zones, which are cooled by means of evaporators connected in series in a coolant circuit, said second injection point enabling the path of the coolant through this evaporator to be shortened. Even with this arrangement, however, an independent cooling of the two storage zones arranged downstream in the coolant circuit is difficult.
DE-OS 1 941 495 discloses a cooling device having three storage zones, to which evaporators arranged in parallel coolant circuits are assigned in each instance. Such a design also enables an arbitrary distribution of the cooling power onto the different storage zones, but the control valves required herefor result in high costs.